Engine-out procedures and eccentric forces on engine pylons

TheSmokingGnu wrote:
Erik wrote:

I love the window seat, but dammit, I cannot look at the wing
ever. "Ok, if it didn't flex like that, it would be brittle
and snap. It's supposed to bounce, it's not supposed to break"

But nothing reassures me.


I find it helps in cases like these to watch a few videos of wing
loading tests, so you can see really just *how* far those wings can go
before breaking.

http://www.youtube.com/watch?v=6Uo0C01Fwb8

TheSmokingGnu

Holy crap. I thought the two to three foot deflection
I've seen was a lot. I had no idea that you could turn
an airplane into a U.

Mxsmanic wrote in
:

Long ago it occurred to me that a twin-engine jet running with one
engine out might be putting tremendous eccentric stress on the plyon
and mounting of the running engine (meaning stress not aligned with
the normal thrust vector of the engine). Today it occurred to me that
this might not be true if the pilots adjust the attitude of the
aircraft so that it is flying straight forward. The adjustments would
create opposing forces that not only keep the aircraft in level flight
but also realign the stress on the running engine, as if there were
still two engines and symmetric forces on the pylons.

Does this make sense?

Nope, pretty much the same as everythign else you post.


Bertie

Mxsmanic wrote in
:

Bob Moore writes:

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

I've seen engine nacelles swaying merrily to and fro (along the wing
axis) in turbulence but I didn't know if twisting forces applied to
the pylons would be so easily tolerated.

Fjukktard



Bertie

I.m wondering if the engineering on wings has changed a bit. I worked for
an airline carrier in the early 60's and we took deliver of the first
boeing 727 built. the company provied us with a very similar video. Its
showed a 727 straped into a cradel and the wings were bent up similar to
what this utube shows..
Difference:
i watched the wings pushed up to where both tips touched each other many
many many times
there was not a failur and i do not remeber exactly how many times but it
was in the dozens. I wonder what the difference is that this wing breaks
after only one raise
tom
"Bertie the Bunyip" wrote in message
.130...
Mxsmanic wrote in
:

Bob Moore writes:

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

I've seen engine nacelles swaying merrily to and fro (along the wing
axis) in turbulence but I didn't know if twisting forces applied to
the pylons would be so easily tolerated.

Fjukktard



Bertie

On 24 May, 21:40, "tom laudato" tommyann wrote:
I.m wondering if the engineering on wings has changed a bit. I worked for
an airline carrier in the early 60's and we took deliver of the first
boeing 727 built. the company provied us with a very similar video. Its
showed a 727 straped into a cradel and the wings were bent up similar to
what this utube shows..
Difference:
i watched the wings pushed up to where both tips touched each other many
many many times
there was not a failur and i do not remeber exactly how many times but it
was in the dozens. I wonder what the difference is that this wing breaks
after only one raise

Nope, essentially the same up to the point where they're sticking
Carbon fiber spars in, but the certification standards are the same.

A wing pylon will happily accept a consideraable load in just about
any flight attitude, what it won't accept is s sudden high G load such
as extreme turbulence or an abrupt engine stoppage might cause.
you won't break a wing off too easily, though.

Bertie

On 23 May, 17:04, Mxsmanic wrote:
Bob Moore writes:
Nope! Back in my B-707 days, the engine was attached to the pylon
with just three bolts about the size of your forefinger, and each of
these bolts was designed to break-away and release the engine before
it could do damage to the wing.

Well, that's certainly reassuring.


Why, what's it matter to you, you don't fly anyway.


Bertie

On May 23, 12:04 pm, Mxsmanic wrote:
Bob Moore writes:
Nope! Back in my B-707 days, the engine was attached to the pylon
with just three bolts about the size of your forefinger, and each of
these bolts was designed to break-away and release the engine before
it could do damage to the wing.

Well, that's certainly reassuring.

Not necessarily. Although it was admittedly caused by maintenance
crew abuse, don't forget the Chicago DC-10 accident, where the engine
came off and caused the deadliest accidental crash in US history.

http://en.wikipedia.org/wiki/America...nes_Flight_191

"Kev" wrote in message
ups.com...
On May 23, 12:04 pm, Mxsmanic wrote:
Bob Moore writes:
Nope! Back in my B-707 days, the engine was attached to the pylon
with just three bolts about the size of your forefinger, and each of
these bolts was designed to break-away and release the engine before
it could do damage to the wing.

Well, that's certainly reassuring.

Not necessarily. Although it was admittedly caused by maintenance
crew abuse, don't forget the Chicago DC-10 accident, where the engine
came off and caused the deadliest accidental crash in US history.

http://en.wikipedia.org/wiki/America...nes_Flight_191


Wow! this is spooky! (from the wiki article cited above)................

"The crash in Chicago remains the most deadly single-aircraft accident in
United States history. Another flight with the same number, Delta Air Lines
Flight 191, crashed at Dallas/Fort Worth International Airport in 1985. Most
recently, Delta Air Lines Flight 5191, operated by Comair as Flight 191,
crashed in 2006 killing 49 people. All three carriers have since retired the
flight number 191, as is currently customary after major accidents on most
airlines. In addition, Puerto Rican airline Prinair also had a fatal flight
numbered Flight 191. The only fatal X-15 crash was also Flight No. 191."

On May 23, 5:11 pm, Erik wrote:
BDS wrote:
"Bob Moore" wrote...

You should see what those pylons do in heavy turbulence!
The only stress is on the pilot who looks at them. :-)

My wife and I were on a flight a few years back in an A300 IIRC and we were
in seats that gave us a clear view of the engine on the left wing. I was
casually looking out at it when I noticed that it was oscillating back and
forth quite noticeably and considerably, and we were only in light chop at
the time. My first impression was HOLY #$%&! quickly followed by the
realization that since it hadn't come off yet it must be normal.

Judging by how much it was moving around you would have thought it was held
on with bungee cords.

BDS

I love the window seat, but dammit, I cannot look at the wing
ever. "Ok, if it didn't flex like that, it would be brittle
and snap. It's supposed to bounce, it's not supposed to break"

But nothing reassures me.-

Understandable. I'd feel the same way if I was you.


Bertie

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